Java Technology

Let's discuss about most important java interview questions : 1) Explain about oops concepts? 2)Explain about memory management i.e. JVM ? 3) What are various modifiers in java ? 4) What is string in java ? Why this is immutable ? 5)What is difference between synchronized block or synchronized method ? 6)How one thread can take two object lock? 7)When we call wait method which class method is called .How its realses lock ? 8)What will happen if class is mutable and used as key in hashmap ? 9)why we create setter getter in pojo classes? 10)How will you design a class to use that class as key in hashmap ? 11)What is memory leak and write a program for memory leak ? 12)explain Hash code and equals method in detail? 13)How hash map work or explain hash map internal working ?

Java is a  programming language  and a  platform independent . Java is a high level, robust, object-oriented and secure programming language. Java was developed by  Sun Microsystems  (which is now the subsidiary of Oracle) in the year 1995.  James Gosling  is known as the father of Java. Before Java, its name was  Oak . Since Oak was already a registered company, so James Gosling and his team changed the Oak name to Java. Platform : Any hardware or software environment in which a program runs, is known as a platform. Since Java has a runtime environment (JRE) and API, it is called a platform.